The intensity of light on a stage is conventionally adjusted by controlling the intensity of light emitted by the light sources illuminating the stage, in order to meet different light requirements. Two blades symmetrically disposed along the axis of the light beam are used to control the light intensity. Each blade is provided with a notch such that the light beam can be shielded to reduce the intensity when both blades move towards each other without changing the shape of the light beam.
When, however, the edge sharpness of the notches are not well controlled due to manufacturing error, the light could be distorted leading to non-uniform dimming and less sharp light spots. Conventional dimming devices therefore include diffusers attached to the blades at a surface away from the light source and extended beyond the periphery of the blades to cover the notches. The light would be diffused when the diffusers move into the beam zone along with the movement of the blades. Nevertheless, due to the fixed attachments of the diffusers with the blades, the trajectory of the diffusers are completely bound to that of the blades, making optimal movement of the atomizer not possible. Moreover, in the event that the machining precision is not high enough such that a slot is formed or interference occurs when the two diffusers reaches to each other, the light would not be diffused completely and an ideal dimming effects is not achievable.